Easy Udon Noodle Soup

Bahan-bahan (1 porsi)

• ½ head Shanghai bok choy ((you can substitute with napa cabbage, green cabbage, or spinach))
• 1½ cups water
• ¼ cup mentsuyu (concentrated noodle soup base)
• 1 serving udon noodles ((frozen, about ½ lb/250 g per serving; I like to use frozen Sanuki udon from Asian/Japanese markets))
• 2 pieces satsumaage (fried fish cakes) ((optional))
• 2 slices kamaboko (fish cake) ((optional))
• 1 soft or hard-boiled egg ((sliced in half))
• shichimi togarashi (Japanese seven spice) ((optional, for a spicy kick))